The present invention relates to an image forming apparatus having, e.g., a facsimile function and a copying function and, more particularly, to an image forming apparatus having a function of issuing reception image data printing start request when the remaining capacity of a reception image memory for storing image data received by facsimile has a predetermined value or less, and detecting at this time whether paper jam has occurred and whether a copying operation has been performed.
To effectively use the printer resource for a printing job, an image forming apparatus having a facsimile function and a copying function has a function of temporarily storing facsimile image data in an image memory to prevent a document being subjected to facsimile communication from occupying the printer, and sequentially transferring the stored image data to a page memory and printing it.
In a communication protocol generally used for a facsimile apparatus, reception completion is returned to the transmission side. To guarantee this, preferably, printing of received image data is started before the image memory for storing received image data becomes full, thereby effectively using the reception image memory and preventing a line disconnection state due to the memory full state.
As far as all transmitted image data are stored in the image memory, even power is turned off or paper jam occurs during printing a received document and image data transferred from the image memory to the page memory is lost, the image data can be read out from the image memory again after power is restored or paper jam is eliminated, so no problem is posed.
In an image forming apparatus having a facsimile function, facsimile image data to be transmitted is temporarily stored in an image memory by transmission reservation. However, the memory may become full. To allow the facsimile reception even in this case, an exclusive reception area is formed in the image memory. However, even this exclusive reception area may become full during storage reception.
When this exclusive reception area becomes full during the storage reception, the former received image is transferred to the page memory while being developed, printing is executed, and just received image data is continuously overwritten in a printing completion area, thereby continuing reception without any interruption. However, the facsimile reception image data cannot sometimes be printed because paper jam has already occurred or because a copying operation has been performed. In the paper jam state, printing cannot be performed. Conventionally, even during the copying operation, the copying operation has priority over the facsimile operation, and facsimile reception image data cannot be printed. Hence, the image memory for facsimile reception often becomes full, resulting in a disadvantage such as line disconnection.
For example, FIG. 12 of Jpn. Pat. Appln. KOKAI Publication No. 5-284265 shows an apparatus having two printers, in which when a FAX function is performed, reception data by the FAX interface section is stored not in a memory on the FAX side but in a memory on the system controller side.
However, the apparatus of this prior art has two printers and is therefore complex and expensive. In addition, when the memory for storing FAX reception data becomes full, the FAX reception line is disconnected.
It is therefore an object of the present invention to provide a convenient image forming apparatus, which can print a facsimile reception image even during a copying operation when a facsimile reception image memory becomes full and minimizes line disconnection.
An image forming apparatus of the present invention is characterized by comprising a reception image memory for storing reception image data, means for checking whether a printing operation using the reception image data stored in the reception image memory can be started when a remaining capacity of the reception image memory has not more than a predetermined value, means for starting printing using the reception image data when it is determined by the checking means that printing is possible, means for, when a printing disable state is detected by the checking means, displaying the printing disable state and checking whether a cause is paper jam, and means for, when the cause is paper jam, causing the reception image memory to continuously receive and store the reception image data.
An image forming apparatus characterized by further comprising, in addition to the above arrangement, interruption designation means for, during an operation of a copying means, designating to interrupt the operation, and means for printing the reception image data in response to the interruption designation.
The apparatus is characterized by further comprising means for causing the copying means to resume the interrupted printing when printing of the reception image data is completed.
According to the present invention, an image forming apparatus in an image data transmission/reception system including first and second apparatuses having reading means, connected to each other through a communication line, for reading originals and converting an read original signal into image data, transmission means for transmitting image data read from the originals, reception means for receiving the image data, and image forming means for forming images of the image data on a target image forming medium, characterized in that each of the first and second apparatuses comprises a reception image memory for storing reception image data, means for checking whether a printing operation using the reception image data stored in the reception image memory can be started when a remaining capacity of the reception image memory has not more than a predetermined value, means for starting printing using the reception image data when it is determined by the checking means that printing is possible, means for, when a printing disable state is detected by the checking means, displaying the printing disable state and checking whether a cause is paper jam or an operation of copying means, means for, when the cause is paper jam, causing the reception image memory to continuously receive and store the reception image data, interruption designation means for, when the cause is the operation of the copying means, designating interruption, and means for printing the reception image data in response to the interruption designation.
According to the present invention, a convenient image forming apparatus which allows an interrupt for printing facsimile reception image data even when a copying operation is being performed in the memory full state of a facsimile reception image memory, and switches the job to preferentially print the facsimile reception image data can be provided.